The first political ideology Venn diagram depicts shared tenets while the second and third bell curve, public goods spectrum diagrams depict the scope of government.
The scope of government* should be determined by allowing taxpayers to directly allocate their individual taxes among the various government organizations. For example, at anytime throughout the year you could visit the Environmental Protection Agency website and directly submit a tax payment. This is known as pragmatarianism and/or tax choice.
Liberals believe that the government should do a lot more (have a broader scope) while conservatives and libertarians believe that the government should do a lot less (have a narrower scope). In a tax choice system, if the Red Cross is more effective and efficient than FEMA then people who value disaster relief might not allocate any of their taxes to FEMA. This would narrow the scope of government. Conversely, because private healthcare is so expensive perhaps more and more taxpayers might allocate their taxes to public healthcare. The amount of money that public healthcare received would determine what percentage of the population qualified for coverage. This would broaden the scope of government. Allowing for a division of labor between taxpayers would reveal the proper scope of government.
One significant problem with the current system is that without allowing taxpayers to consider the opportunity costs of their taxes then there's no way for the government to know how to prioritize spending. Somebody can say that they value defense, public healthcare, infrastructure, etc but the only way to accurately determine exactly how much they truly value infrastructure is by giving them the freedom to choose how much defense and public healthcare they would be willing to forgo in order to pay for more infrastructure. Tax choice allows taxpayers to reveal their preferences which is the only way that public funds can be efficiently distributed among the various government organizations.
Pragmatarianism also solves the problem of government inefficiency. Organizations in the private sector are forced to operate efficiently or they either lose customers (in the case of businesses) or they lose donors (in the case of non-profits). Government organizations currently receive the same amount of money irrespective of how well they use it. Without a strong incentive to operate efficiently they have become extremely inefficient. With pragmatarianism, taxpayers would not willingly give their taxes to a government organization that would just waste their money.
*For a highly entertaining yet very informative historical perspective on the scope of government please see Herbert Spencer's comment at the end of my post on Absurdity-Spotting.
Here is the political ideology Venn diagram. This diagram helps illustrate that libertarian socialism can more accurately be thought of as anarcho-socialism.
Here is the public goods spectrum / scope of government bell curve diagram. On the far left the government would provide all the goods (socialism) and on the far right the market would provide all the goods (anarcho-capitalism). As I mentioned above, allowing for a division of labor between taxpayers would reveal the ideal division of labor between the public and private sectors.
Here is the same public goods spectrum / scope of government bell curve diagram. The difference is that it depicts the liberal spectrum.
Thanks to karmaisking for his suggestion to include control of money/banks on the diagrams!